FIG. 1 shows a top view of a set of rods 12a-f of increasing diameter used for cervical dilation. The rods 12a-f are generally metallic and rigid and come in sets of six pieces, with each of the rods 12a-f including two distinct diameters, a different diameter for each end of the respective rod 12a-f. Thus, the set of rods 12a-f includes twelve total diameters that graduate from a smallest size, for example, 4 mm to 6 mm, in rod 12a to a largest size, for example, 9 mm to 11 mm, in rod 12f. Practitioners performing cervical dilation, such as obstetricians and gynecologists, must insert and remove the rods 12a-f in a graduated order from rod 12a to rod 12f to dilate a cervix of a patient and allow easier access to a uterus of the patient, for example, to investigate uterine bleeding or perform various procedures within the uterus. The use of the set of rods 12a-f to dilate the cervix may take several minutes, is subject to error given a possible out of sequence insertion process, and can expose the patient to twelve separate insertions, each of which may cause damage to the vagina, the cervix, the uterus, or the bowel of the patient, perforate or puncture major blood vessels proximate to these organs, and/or introduce a source of infection to the patient during the twelve-step dilation process.
FIG. 2 shows a cross-sectional view of pelvic anatomy of a patient undergoing the process of cervical dilation using rod 12a of FIG. 1. Though rod 12a is shown, the process of cervical dilation would require inserting and removing both ends of most or all of the rods 12a-f progressing from rod 12a to rod 12f. The rod 12a is being inserted into a cervix 14 after having passed through the patient's labia 16 and vagina 18. Directly below the vagina 18 is the patient's rectum 20, and directly above the vagina 18 is the patient's bladder 22, urethra 24, and clitoris 26. Each of the organs proximate to the vagina 18, that is, any of the rectum 20, the bladder 22, the urethra 24, and the clitoris 26, is susceptible to damage by the rod 12a, the damage taking the form of bruising, scraping, puncture, etc. This susceptibility can be twelve-fold in that both ends of several to all of the rods 12a-f are inserted and removed by the practitioner to perform cervical dilation.
FIG. 2 also shows a uterus 28, the front portion of which is the cervix 14, a middle portion of which is an endometrial canal 30, and end portion of which is a uterine fundus 31. A fallopian tube 32 extends from one side of the endometrial canal 30 to an ovary 34. Though a single fallopian tube 32 and ovary 34 are shown, pairs are generally present. Before completing dilation of the cervix 14, a practitioner may use one of the smaller rods 12a-f, such as rod 12a, to determine a total length or depth of the uterus 28, also known as “sounding” the uterus 28, by passing an end of the rod 12a through the cervix 14, along the endometrial canal 30, until the end of the rod 12a interfaces with the uterine fundus 31. Based on the solid, metallic composition of the rods 12a-f as well as the potential for operator error or misstep, the endometrial canal 30 and the uterine fundus 31 are at risk for puncture, scraping, or other injury during the sounding process. Further, during cervical dilation, any one of the rods 12a-f may inadvertently pass beyond the cervix 14 and into the endometrial canal 30 in a manner such that an end of the respective rod 12a-f impacts sides of the endometrial canal 30 or the uterine fundus 31 in a traumatic manner to cause abrasion, bleeding, puncture, etc. The existing uterine sounding and cervical dilation processes described in respect to FIG. 1 and FIG. 2 are lengthy in time, susceptible to operator error, and complicated with twelve potential instances to introduce injury or infection to the patient.